1. Field of the Invention
This invention relates generally to a method and apparatus for packaging, mixing and delivering bone cement and, more particularly, to a method and apparatus for mixing at least two or more components of the bone cement and delivering the bone cement to a desired surgical site in a convenient manner.
2. Discussion of the Related Art
The natural joints of the body often undergo degenerative changes due to a variety of etiologies. When these degenerative changes become so far advanced and irreversible, it may ultimately become necessary to replace a damaged joint with a prosthetic device. When such replacement becomes necessary, the prosthetic device that is implanted into the body is often secured to the natural bone by use of bone cement.
Other uses of bone cement include repairing or mending bone fractures or shattering of bone that may occur from extreme trauma. Bone cement may also be used for cosmetic or dental surgery as well. Moreover, bone cement may be used as a drug delivery or release system, whereby the bone cement is mixed with antibiotics or other desired drugs and applied to a specific surgical site such that the drugs leach out and are delivered directly to the surgical site. Some bone cements are also resorbable such that the bone cement is resorbed by the body over time.
When referring to bone cement herein, it will be understood that bone cement includes any type of surgical cement used with any type of surgical procedure including resorbable bone cement, bone graft material, bone substitute, bone filler, grouting material, morselized bone graft material, any other biologically compatible mixture which requires at least two or more components, or the bone cements set forth in U.S. Pat. No. 5,149,368 to Liu et al., U.S. Pat. No. 5,281,265 to Liu and U.S. Pat. No. 5,676,976 to Lee, all of which are hereby incorporated by reference.
The above-identified bone cement is generally a two-part material, one being a powder and the other being a liquid which requires the bone cement to be mixed prior to use. One method of mixing these products involves measuring and pouring each component into a bowl and mixing the components with a spatula or other mixing device. This technique is, however, also messy, inconvenient and may create voids or air pockets within the mixture. This technique also may lead to contamination of the bone cement during the mixing process and is very time consuming. As a result, surgical time and cost is generally increased. Moreover, bone cement generally has a specific setup time which also puts a further constraint on the surgeon to mix and deliver the bone cement to the surgical site in a timely manner. Still further, preparation of some bone cements yield offensive vapors. These vapors generally must be evacuated during the mixing, thus adding an additional step or process to the preparation of the bone cement. Still even further, in order to apply the bone cement to the desired surgical site, the bone cement is generally removed from the mixing bowl and delivered to a separate delivery system thereby potentially wasting and contaminating the bone cement, and further increasing the surgical time and cost.
What is needed then is a method and apparatus for packaging, mixing and delivering bone cement which does not suffer from the above mentioned disadvantages. This in turn, will reduce the overall surgical time, decrease surgical cost, reduce the potential for contamination of the bone cement, reduce or eliminate offensive vapors, provide a prepackaged mixing and delivery system which is convenient to use, provide a delivery system that is easily or automatically filled and provide a delivery system which requires a smaller incision to deliver the bone cement to the surgical site. It is, therefore, an object of the present invention to provide such a method and apparatus for packaging, mixing and delivering bone cement.